I am now in the process of cleaning and preserving the skull and mandible.
The pics below show the piece after a basic clean, this Equus piece shows no signs of use by man either for transport or work.
I have tested for magnetic content and again have found this skull and mandible like a lot of other mineralised bones excavated in the south west of Cleveland attract a magnet, as ive stated before I believe this is because the animals absorbed some form of Magnetite, either when alive or during burial.
Note the round magnet attached to the bone outlined in red.